Colon and rectal cancers are leading causes of cancer-related mortality. Colon and rectal cancer are often collectively referred to as colorectal cancer. Colorectal cancer is the fourth most common cancer in the world and it ranks second in terms of cancer deaths in the United States for men, and third for women. In the United States, 55,000 people die of colorectal cancer each year. The incidence of colorectal cancer is similar for men and women except in high-incidence areas where rates for men exceed women by 20%. In addition, the incidence of rectal cancer is 1.5-2 times as likely in men as in women. Although the epidemiology is somewhat different for colon and rectal cancer, data suggest that dietary risk factors are similar.
Colorectal cancer usually develops slowly and progresses through stages described as the adenoma-carcinoma sequence. The initial event in this sequence is the development of aberrant crypt foci (ACF). Subsequently, an adenomatous polyp arises and over time develops into an early malignancy. This early malignancy sequence can take 10-15 years. The development of an adenomatous polyp can be a precursor for colorectal cancer.
The majority of sporadic colon and rectal cancers can occur in adenomas secondary to dysregulation of proto-oncogenes, loss of tumor suppressor gene function, and DNA mismatch repair. These defects result in more localized disease despite the widespread exposure of the colon to various environmental factors, whereas patients who inherit cancer syndromes tend to develop numerous polyps. The progression of aberrant crypt foci (ACF) to polyps is associated with up-regulation of COX-2, inducible NO synthase (INOS) and hydroxy methyl glutaryl CoA reductase (HMG-CoA reductase).
Despite improvement in screening practices, surgical techniques, and adjuvant therapy, the mortality rate from colorectal cancer has decreased by only 1.8% per year over the last 15 years. Therefore, primary prevention of colorectal cancer is an important goal. What is needed is a dietary supplement which can provide ingredients to the body to help prevent colorectal adenomatous polyps and colorectal cancers by maintaining the body's proper tumor suppressor gene and DNA mismatch repair functionality.